source: rtems/cpukit/libfs/src/jffs2/src/compr_zlib.c @ 672038b

4.11
Last change on this file since 672038b was 0c0f128, checked in by Sebastian Huber <sebastian.huber@…>, on Sep 12, 2013 at 1:57:47 PM

JFFS2: Import from Linux

Import of Journalling Flash File System, Version 2 from Linux 3.11.
This part of the Linux kernel is under a separate license which is
similar to the RTEMS license.

The file "cpukit/libfs/src/jffs2/include/linux/jffs2.h" is a copy of
"linux-3.11/include/uapi/linux/jffs2.h".

The file "LICENSE.JFFS2" is a copy of "linux-3.11/fs/jffs2/LICENCE".

The files

"linux-3.11/fs/jffs2/LICENCE",
"linux-3.11/fs/jffs2/acl.h",
"linux-3.11/fs/jffs2/build.c",
"linux-3.11/fs/jffs2/compr.c",
"linux-3.11/fs/jffs2/compr.h",
"linux-3.11/fs/jffs2/compr_rtime.c",
"linux-3.11/fs/jffs2/compr_rubin.c",
"linux-3.11/fs/jffs2/compr_zlib.c",
"linux-3.11/fs/jffs2/debug.c",
"linux-3.11/fs/jffs2/debug.h",
"linux-3.11/fs/jffs2/erase.c",
"linux-3.11/fs/jffs2/gc.c",
"linux-3.11/fs/jffs2/jffs2_fs_i.h",
"linux-3.11/fs/jffs2/jffs2_fs_sb.h",
"linux-3.11/fs/jffs2/nodelist.c",
"linux-3.11/fs/jffs2/nodelist.h",
"linux-3.11/fs/jffs2/nodemgmt.c",
"linux-3.11/fs/jffs2/read.c",
"linux-3.11/fs/jffs2/readinode.c",
"linux-3.11/fs/jffs2/scan.c",
"linux-3.11/fs/jffs2/summary.h",
"linux-3.11/fs/jffs2/write.c", and
"linux-3.11/fs/jffs2/xattr.h"

are copied to "cpukit/libfs/src/jffs2/src".

  • Property mode set to 100644
File size: 5.5 KB
Line 
1/*
2 * JFFS2 -- Journalling Flash File System, Version 2.
3 *
4 * Copyright © 2001-2007 Red Hat, Inc.
5 * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
6 *
7 * Created by David Woodhouse <dwmw2@infradead.org>
8 *
9 * For licensing information, see the file 'LICENCE' in this directory.
10 *
11 */
12
13#if !defined(__KERNEL__) && !defined(__ECOS)
14#error "The userspace support got too messy and was removed. Update your mkfs.jffs2"
15#endif
16
17#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18
19#include <linux/kernel.h>
20#include <linux/zlib.h>
21#include <linux/zutil.h>
22#include "nodelist.h"
23#include "compr.h"
24
25        /* Plan: call deflate() with avail_in == *sourcelen,
26                avail_out = *dstlen - 12 and flush == Z_FINISH.
27                If it doesn't manage to finish, call it again with
28                avail_in == 0 and avail_out set to the remaining 12
29                bytes for it to clean up.
30           Q: Is 12 bytes sufficient?
31        */
32#define STREAM_END_SPACE 12
33
34static DEFINE_MUTEX(deflate_mutex);
35static DEFINE_MUTEX(inflate_mutex);
36static z_stream inf_strm, def_strm;
37
38#ifdef __KERNEL__ /* Linux-only */
39#include <linux/vmalloc.h>
40#include <linux/init.h>
41#include <linux/mutex.h>
42
43static int __init alloc_workspaces(void)
44{
45        def_strm.workspace = vmalloc(zlib_deflate_workspacesize(MAX_WBITS,
46                                                        MAX_MEM_LEVEL));
47        if (!def_strm.workspace)
48                return -ENOMEM;
49
50        jffs2_dbg(1, "Allocated %d bytes for deflate workspace\n",
51                  zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL));
52        inf_strm.workspace = vmalloc(zlib_inflate_workspacesize());
53        if (!inf_strm.workspace) {
54                vfree(def_strm.workspace);
55                return -ENOMEM;
56        }
57        jffs2_dbg(1, "Allocated %d bytes for inflate workspace\n",
58                  zlib_inflate_workspacesize());
59        return 0;
60}
61
62static void free_workspaces(void)
63{
64        vfree(def_strm.workspace);
65        vfree(inf_strm.workspace);
66}
67#else
68#define alloc_workspaces() (0)
69#define free_workspaces() do { } while(0)
70#endif /* __KERNEL__ */
71
72static int jffs2_zlib_compress(unsigned char *data_in,
73                               unsigned char *cpage_out,
74                               uint32_t *sourcelen, uint32_t *dstlen)
75{
76        int ret;
77
78        if (*dstlen <= STREAM_END_SPACE)
79                return -1;
80
81        mutex_lock(&deflate_mutex);
82
83        if (Z_OK != zlib_deflateInit(&def_strm, 3)) {
84                pr_warn("deflateInit failed\n");
85                mutex_unlock(&deflate_mutex);
86                return -1;
87        }
88
89        def_strm.next_in = data_in;
90        def_strm.total_in = 0;
91
92        def_strm.next_out = cpage_out;
93        def_strm.total_out = 0;
94
95        while (def_strm.total_out < *dstlen - STREAM_END_SPACE && def_strm.total_in < *sourcelen) {
96                def_strm.avail_out = *dstlen - (def_strm.total_out + STREAM_END_SPACE);
97                def_strm.avail_in = min((unsigned)(*sourcelen-def_strm.total_in), def_strm.avail_out);
98                jffs2_dbg(1, "calling deflate with avail_in %d, avail_out %d\n",
99                          def_strm.avail_in, def_strm.avail_out);
100                ret = zlib_deflate(&def_strm, Z_PARTIAL_FLUSH);
101                jffs2_dbg(1, "deflate returned with avail_in %d, avail_out %d, total_in %ld, total_out %ld\n",
102                          def_strm.avail_in, def_strm.avail_out,
103                          def_strm.total_in, def_strm.total_out);
104                if (ret != Z_OK) {
105                        jffs2_dbg(1, "deflate in loop returned %d\n", ret);
106                        zlib_deflateEnd(&def_strm);
107                        mutex_unlock(&deflate_mutex);
108                        return -1;
109                }
110        }
111        def_strm.avail_out += STREAM_END_SPACE;
112        def_strm.avail_in = 0;
113        ret = zlib_deflate(&def_strm, Z_FINISH);
114        zlib_deflateEnd(&def_strm);
115
116        if (ret != Z_STREAM_END) {
117                jffs2_dbg(1, "final deflate returned %d\n", ret);
118                ret = -1;
119                goto out;
120        }
121
122        if (def_strm.total_out >= def_strm.total_in) {
123                jffs2_dbg(1, "zlib compressed %ld bytes into %ld; failing\n",
124                          def_strm.total_in, def_strm.total_out);
125                ret = -1;
126                goto out;
127        }
128
129        jffs2_dbg(1, "zlib compressed %ld bytes into %ld\n",
130                  def_strm.total_in, def_strm.total_out);
131
132        *dstlen = def_strm.total_out;
133        *sourcelen = def_strm.total_in;
134        ret = 0;
135 out:
136        mutex_unlock(&deflate_mutex);
137        return ret;
138}
139
140static int jffs2_zlib_decompress(unsigned char *data_in,
141                                 unsigned char *cpage_out,
142                                 uint32_t srclen, uint32_t destlen)
143{
144        int ret;
145        int wbits = MAX_WBITS;
146
147        mutex_lock(&inflate_mutex);
148
149        inf_strm.next_in = data_in;
150        inf_strm.avail_in = srclen;
151        inf_strm.total_in = 0;
152
153        inf_strm.next_out = cpage_out;
154        inf_strm.avail_out = destlen;
155        inf_strm.total_out = 0;
156
157        /* If it's deflate, and it's got no preset dictionary, then
158           we can tell zlib to skip the adler32 check. */
159        if (srclen > 2 && !(data_in[1] & PRESET_DICT) &&
160            ((data_in[0] & 0x0f) == Z_DEFLATED) &&
161            !(((data_in[0]<<8) + data_in[1]) % 31)) {
162
163                jffs2_dbg(2, "inflate skipping adler32\n");
164                wbits = -((data_in[0] >> 4) + 8);
165                inf_strm.next_in += 2;
166                inf_strm.avail_in -= 2;
167        } else {
168                /* Let this remain D1 for now -- it should never happen */
169                jffs2_dbg(1, "inflate not skipping adler32\n");
170        }
171
172
173        if (Z_OK != zlib_inflateInit2(&inf_strm, wbits)) {
174                pr_warn("inflateInit failed\n");
175                mutex_unlock(&inflate_mutex);
176                return 1;
177        }
178
179        while((ret = zlib_inflate(&inf_strm, Z_FINISH)) == Z_OK)
180                ;
181        if (ret != Z_STREAM_END) {
182                pr_notice("inflate returned %d\n", ret);
183        }
184        zlib_inflateEnd(&inf_strm);
185        mutex_unlock(&inflate_mutex);
186        return 0;
187}
188
189static struct jffs2_compressor jffs2_zlib_comp = {
190    .priority = JFFS2_ZLIB_PRIORITY,
191    .name = "zlib",
192    .compr = JFFS2_COMPR_ZLIB,
193    .compress = &jffs2_zlib_compress,
194    .decompress = &jffs2_zlib_decompress,
195#ifdef JFFS2_ZLIB_DISABLED
196    .disabled = 1,
197#else
198    .disabled = 0,
199#endif
200};
201
202int __init jffs2_zlib_init(void)
203{
204    int ret;
205
206    ret = alloc_workspaces();
207    if (ret)
208            return ret;
209
210    ret = jffs2_register_compressor(&jffs2_zlib_comp);
211    if (ret)
212            free_workspaces();
213
214    return ret;
215}
216
217void jffs2_zlib_exit(void)
218{
219    jffs2_unregister_compressor(&jffs2_zlib_comp);
220    free_workspaces();
221}
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